Melanoma skin cancer can be fatal unless caught early, but most skin lesions are harmless. Dermoscopy with training can help with diagnosis. This blog is not a substitute for a medical opinion-if you are worried about a changing or funny looking mole or spot, get it checked by a doctor with suitable skills.

A solitary pink nodule on sun damaged skin

All the experts are agreed-if you get a new, firm, growing nodule -especially in sun damaged white skin-you had better be concerned. Here is a pink nodule, but as it was on the person’s back, it was not clear how long it had been there. You can see the skin is sun damaged from the freckles.

How worrying is this to the naked eye? Its not very dramatic, but there is that dark blob.

let’s get the scope on it.

We now have a much clearer view and more information to make a diagnosis.

-an irregular pigmented structure (again, call it a blue-grey ovoid nest or a blue clod, its the same thing)

-shiny white structures (used to be called chrysalis sign, a term best avoided)

These are all features of a basal cell cancer. The diagnosis is very clear with dermoscopy, whereas with the naked eye all you could say is that it could be a lot of different things. Treatment is excision with a 4mm margin, cryotherapy or topical therapy should not be attempted as this is a nodular lesion.

PS by the ultra-simple Kittler method (chaos and clues), we ask-is the lesion chaotic? (i.e. does it have multiple colours and structures?) The answer is clearly yes. We then ask-is it a seborrhoeic keratosis? There are zero features to allow this diagnosis. We therefore can go straight to excision. If we want to apply a more detailed version of the Kittler method, we look for clues, in particular clues to malignancy. Of these, there are many. Shiny white structures, irregular vessels and blue clods will do.

Using the Henderson/Hayes SCOPE mnemonic, we begin by looking for SYMMETRY. The lesion is not symmetrical for colour or structure (shape is quite symmetrical but that is less important than symmetry of colour and structure. So that’s a fail.

then we COUNT the Colours-I can see red, white and blue (we could maybe add pink to red, but there is no need as 3 colours is quite bad enough)

count the PATTERNS, there is amorphous, red lines (the vessels) white clods and blue clods. Too many patterns.

The EDGE is unremarkable, but we already have enough evidence for excision.

Finally, the HEURISTIC method (heuristic+Eureka!). When you have studied a few hundred lesions like this, you will take one look at the dermoscopic image and say ‘It’s a BCC’ in one second. If it looks like an elephant, it’s most likely an elephant. This is a very typical example of a nodular BCC, and perhaps it takes no great skill to say so, but the more examples you see, the better you will get, and getting used to these signs in the typical and regular form will help you pick them up when seen in subtler guises.